Ultra-processed foods, which now account for over 50% of dietary energy intake in high-income countries, are increasingly linked to the development of allergies and asthma in children, according to research presented at the American Thoracic Society (ATS) 2025 International Conference in San Francisco.
Lisa G. Wood, PhD, a professor at the University of Newcastle and researcher at the Hunter Medical Research Institute, highlighted findings from a systematic review published in Pediatric Allergy and Immunology that examined the relationship between ultra-processed foods and respiratory health outcomes in pediatric populations.
Systematic Review Reveals Strong Associations
The systematic review analyzed multiple studies examining the connection between ultra-processed food consumption and respiratory diseases in children. "This paper was a systematic review of the literature, and it looked at the association between ultra-processed foods allergies and asthma," Wood explained. "They did actually find quite a number of studies that demonstrated a link between ultra-processed foods and the development of allergies and asthma in children."
The research revealed that ultra-processed foods—defined as industrially produced foods that are "very far away from whole foods" and manufactured with different nutrient compositions—have measurable impacts on children's immune systems. According to the findings, these foods "altered the gut microbiome and caused immune dysregulation," providing a potential mechanistic explanation for their association with respiratory diseases.
Metabolic Dysfunction and Respiratory Health
Beyond ultra-processed foods, Wood's presentation also covered research examining the triglyceride glucose index as a measure of metabolic dysfunction. This research demonstrated an association between a high triglyceride glucose index, indicating metabolic impairment, and increased asthma risk. The triglyceride glucose index is commonly linked to obesity, creating additional pathways through which poor diet quality can influence respiratory health.
"People in lower socioeconomic areas are more likely to be obese," Wood noted. "They're more likely to have problems with glucose metabolism, to have metabolic syndrome and insulin resistance, making them predisposed to asthma and allergies. So there are multiple ways where a poor quality diet can contribute to the development of asthma and allergy."
Socioeconomic Barriers to Healthy Nutrition
The research highlighted significant disparities in food access based on geographic and socioeconomic factors. "It's just an unfortunate fact that people who are living in certain geographical areas, typically those that are of low socioeconomic status, the access to fresh and healthy foods is less," Wood explained.
These access limitations create a cycle where populations already at higher risk for respiratory diseases face additional barriers to preventive nutrition. The combination of limited access to whole foods and increased reliance on ultra-processed alternatives compounds the risk factors for developing asthma and allergies in childhood.
Clinical Implications and Future Directions
While Wood acknowledged that some studies did not demonstrate effects on asthma or lung health related to ultra-processed foods, she emphasized that the volume of research pointing to connections was significant enough to warrant further investigation. "It really directs researchers to go and look further to understand why this is occurring," she said. "That will allow us to develop some therapeutic strategies, or intervention strategies to avoid the negative effects of ultra-processed foods."
For healthcare providers, Wood emphasized the importance of prioritizing nutrition in respiratory care. "I think that I would really like to see that pulmonologists actually prioritize nutrition for their patients," she said. "Nutrition, as I mentioned, isn't automatically something that everybody links to respiratory health."
The research team at the University of Newcastle has been examining the relationship between nutrition and respiratory disease for over 20 years, focusing particularly on effects across the lifespan, with childhood nutrition representing a key area of investigation. Wood noted that historically, there has been limited research linking nutrition and respiratory outcomes, making these findings particularly significant for understanding preventive approaches to pediatric respiratory health.